The present invention relates to a dental press for removing and installing components of a dental handpiece and especially to a press having a jig therein for removing the bearing from a dental handpiece and attaching a new bearing therein.
Dental handpieces are commonly used in connection with dental instruments in the dentist's office and are typically held by the dentist while performing cleaning, drilling or other functions on a patient's teeth. The handpiece has a rotating shaft on one end which has different removable attachments for cleaning and polishing the teeth and the like. The handpiece attachments are quickly changed from one to another on the end of the rotating shaft of the handpiece. A dentist's office typically has more than one handpiece for working on patients. Dental handpieces are subject to bearing use and have to be rebuilt or repaired on a regular basis as the bearings wear out. It is common to repair such items by sending them back to the factory for either a new dental handpiece or to rebuild the worn or broke handpiece by removing and replacing the bearings. The bearings are located in the head of the handpiece and are pressed onto a spindle along with an impeller. The spindle, bearings, and impeller make up the component which the present machine rebuilds and is referred to as the handpiece turbine.
The present invention is for a small hand press having a frame which has a handle driving a gear and rack to actuate the press. A jig is designed to be placed in the press and has a base for supporting the dental handpiece turbine therein and has a push plate slidably mounted over the base and having a pair of rams attached thereon for driving a spindle from the handpiece turbine through an opening in the base plate and a second ram for forcing a new bearing onto the spindle. The press advantageously allows for the alignment of the bearings and the supporting of the bearings during the fitting of a new bearing into the handpiece turbine and in the removal of the old bearings. This allows the dentist to replace the bearings in a handpiece in his office at a small expense and thus have the use of the dental handpiece immediately rather than having to send the handpiece back to the factory to have the bearings replaced. This also substantially reduces the cost to the dentist in maintaining his equipment.
Large and small arbor and other types of presses have been common in the prior art including various types of hand presses which use a hand actuated arm rotating a gear to drive a rack, as in the present preferred embodiment. Other types of presses use a handle which acts as a lever arm to gain a mechanical advantage in driving the press while yet others use hydraulic rams to drive the press which rams are actuated by hydraulic pumps. In addition, presses and pin extractors can use a threaded shaft to gain the mechanical advantage of a screw in driving pins or components with a large mechanical force.
Prior art presses or extractors can be seen in the Pabst U.S. Pat. No. 1,800,566, for an apparatus for removing commutators from armature shafts which uses a press having a hand lever rotating a gear to drive a rack to drive a plunger for removing commutators from the armature shaft. In the Taylor U.S. Pat. No. 2,485,022, a cross-head for presses is for a manually operated arbor press using a threaded driving shaft as a press screw in the press. Similarly, the Maynard patent, No. 4,977,660, is a tool for removing and installing an automotive universal joint which has a push rod in a press for removing an automotive universal joint. The Gould U.S. Pat. No. 4,305,195, is an apparatus for disassembling and assembling skate wheels which has a pin actuated arm for driving a push/pull member for removing the bearings of a skate wheel and for reinstalling the bearings on the skate wheel. The Schneider U.S. Pat. No. 4,118,852, is for a piston pin remover and installer for use in automobile engine pistons for repair and replacement of a pair of new pins in the piston. The Miller U.S. Pat. No. 2,267,662, is for a press which uses a hydraulic jack for driving a push-type plate against a pair of springs to thereby drive a plunger. The Veilleux U.S. Pat. No. 2,629,442, is a tool for removing rivets and burrs and it has a hand actuating arm driving a cam to thereby drive a plunger.
In contrast to this prior art and the many other prior patents for various types of push/pull instruments, the present invention is for a specific press and jig for supporting and removing the bearings from a dental handpiece turbine and for holding a new bearing and reinstalling the bearing onto the handpiece turbine and uses special ram members for supporting and aligning members with the dental handpiece turbine to facilitate the rapid removal and installation of components.